1. Field of the Invention
The present invention relates to a novel headlamp device for a vehicle. More specifically, the invention relates to a technique for obtaining optimum light distribution corresponding to various running situations of a vehicle.
2. Description of the Related Art
In a conventional headlamp device for a vehicle, an irradiation range is limited in order to prevent a glare from being given to a car running in the opposite direction and a car running ahead. Therefore, there is a problem in that irradiation is not carried out in a turning direction to be a direction in which a driver wants to perform observation most greatly during turning.
There has been proposed a headlamp device for a vehicle using a lateral light distribution control method in which a reflector is rotated in a lateral direction depending on a progress direction, thereby turning light distribution in the direction of the sight line of a driver.
The conventional headlamp device for a vehicle using a lateral light distribution control method has such a structure that a reflector is rotated laterally with respect to a body fixed to a vehicle body. Therefore, there is a problem in that the rotating shaft of the reflector is tilted with respect to the ground when the pitch angle of the vehicle body fluctuates. When the reflector is rotated laterally with the rotating shaft tilted with respect to the ground, the locus of movement in an irradiating position onto a road with the rotation is not described circularly so that a state of distortion is brought. Consequently, the distortion of a light distribution pattern for irradiating the road or the distortion of a cut line is generated (FIGS. 9(a) to 9(c) show a light distribution pattern “a” obtained when the reflector is rotated to the left, FIG. 9(a) showing the case in which the pitch angle is zero, that is, the vehicle is set in a horizontal state, FIG. 9(b) showing the case in which the vehicle is tilted forward, and FIG. 9(c) showing the case in which the vehicle is tilted rearward), and a visibility is adversely affected and a glare is given to a car running in the opposite direction, and furthermore, a feeling of physical disorder is given to a driver.